排序方式: 共有15条查询结果,搜索用时 15 毫秒
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Toppani A Robert F Libourel G de Donato P Barres O d'Hendecourt L Ghanbaja J 《Nature》2005,437(7062):1121-1124
The signature of carbonate minerals has long been suspected in the mid-infrared spectra of various astrophysical environments such as protostars. Abiogenic carbonates are considered as indicators of aqueous mineral alteration in the presence of CO2-rich liquid water. The recent claimed detection of calcite associated with amorphous silicates in two planetary nebulae and protostars devoid of planetary bodies questions the relevance of this indicator; but in the absence of an alternative mode of formation under circumstellar conditions, this detection remains controversial. The main dust component observed in circumstellar envelopes is amorphous silicates, which are thought to have formed by non-equilibrium condensation. Here we report experiments demonstrating that carbonates can be formed with amorphous silicates during the non-equilibrium condensation of a silicate gas in a H2O-CO2-rich vapour. We propose that the observed astrophysical carbonates have condensed in H2O(g)-CO2(g)-rich, high-temperature and high-density regions such as evolved stellar winds, or those induced by grain sputtering upon shocks in protostellar outflows. 相似文献
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A. Bolognari Antonina Donato Celi P. Motta L. Squeri 《Cellular and molecular life sciences : CMLS》1965,21(11):642-644
Summary The authors found several modifications, particularly in the nucleolus, in kidney epithelial cells ofMacaca mulatta, kept in culture for 6–8 days, after infection with polio and Coxsackie viruses. They observed, after infection with polio virus, some groups of virus-like bodies, which indicate the possibility that a provocation took place in it. 相似文献
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Antonina Donato Celi Loredana d'Este Diana Teti 《Cellular and molecular life sciences : CMLS》1967,23(6):433-434
Summary The researches carried out both under the light and electron microscopes permitted us to ascertain that, in EchinodermataArbacia lixula andSphaerechinus granularis, yolk globules form by aggregation of ribonucleoproteic particles. It appears that the globules themselves in the first stage of their formation show such physico-chemical conditions as to condition the precipitation of silver in the method used to reveal Golgi apparatus. 相似文献
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Rosario Donato Guglielmo Sorci Ileana Giambanco 《Cellular and molecular life sciences : CMLS》2017,74(15):2749-2760
S100A6 protein belongs to the A group of the S100 protein family of Ca2+-binding proteins. It is expressed in a limited number of cell types in adult normal tissues and in several tumor cell types. As an intracellular protein, S100A6 has been implicated in the regulation of several cellular functions, such as proliferation, apoptosis, the cytoskeleton dynamics, and the cellular response to different stress factors. S100A6 can be secreted/released by certain cell types which points to extracellular effects of the protein. RAGE (receptor for advanced glycation endproducts) and integrin β1 transduce some extracellular S100A6’s effects. Dosage of serum S100A6 might aid in diagnosis in oncology. 相似文献
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Voltage-gated potassium channels such as Shaker help to control electrical signalling in neurons by regulating the passage of K+ across cell membranes. Ion flow is controlled by a voltage-dependent gate at the intracellular side of the pore, formed by the crossing of four alpha-helices--the inner-pore helices. The prevailing model of gating is based on a comparison of the crystal structures of two bacterial channels--KcsA in a closed state and MthK in an open state--and proposes a hinge motion at a conserved glycine that splays the inner-pore helices wide open. We show here that two types of intersubunit metal bridge, involving cysteines placed near the bundle crossing, can occur simultaneously in the open state. These bridges provide constraints on the open Shaker channel structure, and on the degree of movement upon opening. We conclude that, unlike predictions from the structure of MthK, the inner-pore helices of Shaker probably maintain the KcsA-like bundle-crossing motif in the open state, with a bend in this region at the conserved proline motif (Pro-X-Pro) not found in the bacterial channels. A narrower opening of the bundle crossing in Shaker K+ channels may help to explain why Shaker has an approximately tenfold lower conductance than its bacterial relatives. 相似文献
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MA Deardorff M Bando R Nakato E Watrin T Itoh M Minamino K Saitoh M Komata Y Katou D Clark KE Cole E De Baere C Decroos N Di Donato S Ernst LJ Francey Y Gyftodimou K Hirashima M Hullings Y Ishikawa C Jaulin M Kaur T Kiyono PM Lombardi L Magnaghi-Jaulin GR Mortier N Nozaki MB Petersen H Seimiya VM Siu Y Suzuki K Takagaki JJ Wilde PJ Willems C Prigent G Gillessen-Kaesbach DW Christianson FJ Kaiser LG Jackson T Hirota ID Krantz K Shirahige 《Nature》2012,489(7415):313-317
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G. Torreggiani A. Lenaers G. Federighi G. Menichini G. Bartolomei L. Donato 《Cellular and molecular life sciences : CMLS》1966,22(2):126-126
Riassunto Il confronto tra i valori del flusso coronarico ottenuti con il metodo della clearance miocardica del Rb-86 e quelli osservati con il metodo del protossido d'azoto è risultato altamente soddisfacente. è stata, pertanto, ulteriormente confermata la validità del metodo della clearance miocardica del Rb-86 nello studio del flusso coronarico nell'uomo.
This work was supported by Euratom Association Contract 026-53-4 BIAC. 相似文献
This work was supported by Euratom Association Contract 026-53-4 BIAC. 相似文献
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A regulatory polymorphism in PDCD1 is associated with susceptibility to systemic lupus erythematosus in humans 总被引:27,自引:0,他引:27
Prokunina L Castillejo-López C Oberg F Gunnarsson I Berg L Magnusson V Brookes AJ Tentler D Kristjansdóttir H Gröndal G Bolstad AI Svenungsson E Lundberg I Sturfelt G Jönssen A Truedsson L Lima G Alcocer-Varela J Jonsson R Gyllensten UB Harley JB Alarcón-Segovia D Steinsson K Alarcón-Riquelme ME 《Nature genetics》2002,32(4):666-669